CHENNAI: 2018 has been the year of extremes globally and India was no exception. Erratic monsoons meant flooding in some region and deficit rainfall in others. While Kerala, for instance, witnessed the worst floods in a century, the monsoon in neighbouring Tamil Nadu failed. For Tamil Nadu, which has a long coastline of over 1,000 km, the past three-four years has been nothing short of a disaster. It was either disruptive rains or failed monsoon.
This, according to KJ Ramesh, Director General of Meteorology, Indian Meteorological Department (IMD), will be the ‘new’ normal and he attributes it to climate change. “State governments should learn to deal with this. Extreme weather events, which includes flooding, drought, hotter summers and cold waves, will become normal.
As per the latest study, half of the measured global precipitation in a year fall in just 12 days and by 2100, climate models predict that this lopsided distribution of rain is likely to be further reduced to 11 days,” he said while giving a detailed presentation at Centre Science and Environment (CSE) in New Delhi before interacting with Express.
Asking coastal states to keep extra vigil on their development along the coast in view of sea level rise, Ramesh has called for multi-hazard proofing of structures and lifeline infrastructure like power transmission lines, towers etc to withstand much stronger winds and cyclones. “Cyclonic storms bring much stronger winds and storms will intensify rapidly due to anomalous warming of Bay of Bengal. Severe cyclonic storm Ockhi is a perfect example. It intensified from depression to severe cyclone in 13 hours,” he said and added that Tamil Nadu is particularly vulnerable to such freak events.
Living in denial?
Ironically, the Union government has been in denial and recently, approved Coastal Regulation Zone (CRZ) Notification, 2018 which beefs-up tourism and construction activity in vulnerable coastal areas. This year, though IMD had predicted above-normal rains for Tamil Nadu, it turned out to be the exact opposite.
S Balachandran, deputy director general of meteorology, Regional Meteorological Centre, Chennai, said: “The reasons for poor monsoons are being analysed. One, the number of rainy days have significantly come down and too many cyclones have taken away moisture over the region,” he said and added that details will be announced after December 31, which is when the monsoon draws to close although the total withdrawal may happen little later.
Kerala floods wake-up call
The IMD chief said Kerala floods should be a wake-up call and the decadal precipitation data shows such extreme rainfall events will repeat. The percentage of “extremely heavy rainfall” and “dry days” has shown an increasing trend in the past few decades while the frequency of “light to moderate” and “very light “rainfall is decreasing in India — one of the many impacts of climate change being observed by IMD.
Ramesh said rainfall data from 1951 to 2016 shows a significant increase in episodes of more than 10-15 cm of rain per day, while instances of moderate rainfall (5 cm a day) are decreasing. The journal Geophysical Research Letters also reported that there has been a marked increase in heavy rainfall events in southern and northwestern India, post-2000.
Sunita Narain, director general of CSE, said “The very definition of what is ‘normal’ is changing. The fact is that Indian monsoon is becoming more extreme and more variable. In this way, the new normal is flood at the time of drought. This is a double whammy. On one hand, we are getting our water management wrong — we are building in floodplains, destroying our waterbodies and filling up our water channels. Chennai or Mumbai or Bengaluru did not drown only because of extreme rain. They drowned also because all drainage systems were willfully destroyed. Our city developers only see land as a building area.”
El Nino developing, hot days ahead
IMD in its ‘seasonal outlook for temperatures’ stated that there would be above normal average temperatures across all meteorological sub-divisions due to influence of a brewing El Nino over Pacific Ocean. El Nino is a climatic phenomenon that occurs due to an abnormal warming of Pacific Ocean and is known to impact global weather patterns. A strong El Nino was reported in 2014 and 2015.